TW201816889A - Deposition method for rapidly recovering the amount of etching of the aluminum fluoride layer in the etching chamber - Google Patents

Abstract

Implementations of the present disclosure provide a chamber component for use in a processing chamber. The chamber component includes a body for use in a plasma processing chamber, a barrier oxide layer formed on at least a portion of an exposed surface of the body, the barrier oxide layer having a density of about 2 gm/cm3 or greater, and an aluminum oxyfluoride layer formed on the barrier oxide layer, the aluminum oxyfluoride layer having a thickness of about 2 nm or greater.

Description

Deposition method for quickly recovering etched amount of fluoroaluminum layer in etching chamber

The large embodiment of the present disclosure relates to improved chamber components and methods for processing chamber components.

Plasma reactors in the semiconductor industry usually consist of aluminum-containing materials. Especially in a polycrystalline silicon, metal or oxide etching chamber, when a fluorine-containing gas such as NF ₃ or CF ₄ is used as an etching chemical, an aluminum fluoride layer can be formed on the aluminum surface. It can be seen that the formation of aluminum fluoride on the surface of the aluminum chamber can cause etch rate drift and chamber instability. Aluminum fluoride on the surface of the chamber can also be peeled off by plasma treatment and contaminate the surface of the substrate to be processed in the chamber with particles.

Therefore, there is a need in the art to provide improved processes for processing chamber components that minimize or avoid etch rate drift issues during processing and the possibility of aluminum fluoride contamination on the substrate surface.

Implementations of the present disclosure provide chamber components for use in a processing chamber. The chamber component includes: a main body used in a plasma processing chamber; an oxide barrier layer formed on at least a portion of an exposed surface of the main body, the oxide barrier layer having about 2 gm / cm ³ or Greater density; and a fluoroaluminum oxide layer formed on the oxide barrier layer, the fluoroaluminum oxide layer having a thickness of about 2 nm or more.

In another implementation, a method for processing a chamber component is provided. The method includes exposing at least a portion of an exposed surface of the chamber component body to oxygen, wherein the exposed surface of the chamber component body includes aluminum; and exposing the chamber component body to a temperature of about 5 ° C to about 50 ° C. It includes hydrofluoric acid (the HF), ammonium fluoride (NH ₄ F), ethylene glycol and water solution for about 30 minutes or longer, in order to convert the oxide barrier layer at least a portion of the aluminum oxide layer with a fluorine.

In yet another implementation, the method includes forming an oxide barrier layer on at least a portion of an exposed surface of the chamber component body, wherein the exposed surface of the chamber component body includes aluminum; and by exposing the chamber component body to Includes about 29% by volume of 49% hydrofluoric acid (HF), about 11% by volume of 40% ammonium fluoride (NH ₄ F), and 60% by volume of 100 at a temperature of about 5 ° C to about 50 ° C. % Ethylene glycol solution for about 30 minutes or more, forming a layer of aluminum fluoride on the oxide barrier layer.

FIG. 1 depicts a flowchart of a method 100 for processing chamber components for use in a substrate processing chamber, such as a plasma processing chamber. FIG. 1 is illustratively described with reference to FIGS. 2A to 2B, which illustrate perspective views of a portion of a chamber component during various stages of a method according to the flowchart of FIG. 1. Those skilled in the art will recognize that the structures shown in FIGS. 2A to 2B are not drawn to scale. In addition, it is envisaged that, although various steps are illustrated in the description herein and the accompanying drawings, no limitation as to the order or existence or absence of intermediate steps with respect to these steps is implied. Unless explicitly specified, the steps depicted or described in order are merely for explanation and do not exclude the possibility that the individual steps are actually performed in parallel or overlapping, if not completely, at least in part.

As shown in FIG. 2A, the method 100 begins at block 102 by providing a chamber component 202. The chamber component 202 may be made of aluminum, stainless steel, aluminum oxide, aluminum nitride, or ceramic. For convenience of explanation, the chamber member 202 is shown in a rectangular shape. It is envisaged that the chamber component 202 may be any part of a plasma processing chamber, such as a chamber wall, a chamber cover, a spray head, a processing accessory ring, a cover, a lining, a base, or an electrical power exposed within the processing chamber. Other replaceable chamber components of the pulp environment. The chamber member 202 has a main body 203. The body 203 may be manufactured from a single piece of material to form a one-piece body, or welded or otherwise joined together to form a one-piece body from two or more components. In various implementations, the chamber component 202 is a one-piece body 203 formed of aluminum. In some implementations, the chamber component 202 may be a one-piece body formed of aluminum-coated stainless steel, where an aluminum coating forms the exposed or outer surface 205 of the body 203. Alternatively, the chamber component 202 may be any one of the core body 207 composed of aluminum or a non-aluminum material coated with aluminum 209 such that the exposed surface or outer surface 211 of the core body 207 is aluminum, as shown in FIG. 2C of. Although aluminum is discussed, it is contemplated that the exposed or outer surface 211 may be made of stainless steel, aluminum oxide, aluminum nitride, or ceramic.

At block 104, an optional oxide barrier layer 204 is formed on the outer surface 205 of the body 203 of the chamber component 202, as shown in FIG. 2A. The oxide barrier layer 204 may be a thin, dense oxide layer. Oxygen-containing gas (which may include, for example, other oxygen-containing gases such as atomic oxygen (O), molecular oxygen (O ₂ ), ozone (O ₃ ), and / or steam (H ₂ O), etc.) may be used to deposit in a high temperature oxidation furnace Thin, dense oxide layer. Other oxygenates such as tetraethyl orthosilicate (TEOS) can also be used. The barrier layer 204 may have an oxide / cm ³ or greater density of about 2gm, for example, from about 5 gm / cm ³ or greater density. The oxide barrier layer 204 may have a thickness of about 2 nm to about 18 nm, such as about 4 nm to about 12 nm, such as about 7 nm to about 10 nm. The thickness of the oxide barrier layer 204 may vary depending on the processing requirements or desired barrier layer life.

In an exemplary implementation, the oxide barrier layer 204 uses ozone and / or TEOS in a sub-atmospheric, non-plasma-based chemical vapor deposition (CVD) processing chamber in a chamber component 202 is formed on the surface. In this case, an annealing process may be performed to harden the oxide barrier layer 204. An exemplary annealing process may include heating the chamber component 202 to a temperature of 850 ° C or higher (eg, 1000 ° C or higher) in a nitrogen environment for about 10 seconds. The resulting oxide barrier layer 204 may have a density of about 10 gm / cm ³ or more, such as a density of about 15 gm / cm ³ or more.

In some implementations, at least a portion of the oxide barrier layer 204 may be a native oxide that is typically formed when the surface of the chamber component 202 is exposed to oxygen. Oxygen exposure occurs when the chamber components are stored under atmospheric conditions, or when a small amount of oxygen is maintained in the vacuum chamber. Alternatively, the entire oxide barrier layer 204 may be a native oxide.

At block 106, the chamber component 202 is processed using a fluorination process such that at least a portion of the oxide barrier layer 204 or the entire oxide barrier layer 204 is converted to an aluminum fluoride layer 206, as shown in FIG. 2B. The aluminum fluorofluoride layer 206 may have a thickness of about 2 nm to about 18 nm, such as about 4 nm to about 12 nm, such as about 7 nm to about 10 nm. The chamber component 202 may be exposed (eg, immersed) to a hydrofluoric acid (HF) -containing, fluorine-containing In a solution of ammonium chloride (NH ₄ F), ethylene glycol, and water (H ₂ O) for about 30 minutes or more, such as about 60 minutes or more, about 120 minutes or more, about 180 minutes, or It takes longer, or about 300 minutes or longer, to perform the fluorination process. Hydrofluoric acid and ammonium fluoride react with each other and with the alumina surface of the chamber member 202 to form an aluminum fluoride layer 206. Specifically, the fluorination process converts a portion or the entire alumina surface into a protective fluorinated aluminum oxide layer 206 on at least a portion of the exposed surface of the chamber component 202. Once the protective fluoroaluminum oxide layer 206 is formed, the underlying aluminum surface is protected from corrosion by acids such as hydrofluoric acid in the solution. Ethylene glycol is also used to slow or delay the etching reaction between the aluminum surface and hydrofluoric acid, thus protecting the underlying aluminum surface from excessive etching of hydrofluoric acid.

The hydrofluoric acid may be a standard HF solution containing 49% by weight of hydrogen fluoride (ie, 49% HF). Ammonium fluoride can be solid or aqueous. In one implementation, an ammonium fluoride solution with a concentration of about 40% by weight of NH ₄ F is used.

In various implementations, the solution may contain about 15% to 45% by volume of 49% HF, about 5% to 25% by volume of 40% NH ₄ F, and about 45% to 75% by volume of 100% B Diol. In an exemplary implementation (Embodiment 1 below), the solution contains about 29% by volume of 49% HF, about 11% by volume of 40% NH ₄ F, and 60% by volume of 100% ethylene glycol. If solid ammonium fluoride is used, the solution may contain about 20% to 40% by volume of 49% HF, about 30g / L to 55g / L of NH ₄ F, and about 50% to 75% by volume of 100% ethylene dichloride. alcohol, and from about 2 vol% to 12 vol% of water (H ₂ O). In an exemplary implementation (the following embodiment 2), the solution contains about 31.6 vol% 49% HF, about 44.6 g / L of NH ₄ F, 63.1 vol% 100% ethylene glycol, and 5.4 vol% water.

The following Table 1 shows the atomic concentration (in%) of the aluminum fluorocarbon layer (10 nm thickness) treated with the solution used in Embodiment 1 under different process times and conditions. The numbers shown in Table 1 are normalized to 100% of the detected elements. No H or He was detected. In addition, a dash "-" indicates an undetected element. Table 1

The test numbers 1 to 4 shown in Table 1 indicate the chamber parts that were immersed in the solution for 30 minutes, 60 minutes, 90 minutes, and 120 minutes, respectively. Specifically, the fluorination process was performed in test numbers 1 to 4 without forming an oxide barrier layer on the surface of the chamber member. Therefore, the aluminum surface of the chamber member 202 may have no native oxide, or may have only a trace amount of native oxide. Test number R indicates a mechanical chamber component that has not undergone any treatment of the fluorination process of the present invention. Test numbers A1 and A2 indicate chamber components that were immersed in the solution for 30 minutes and 60 minutes, respectively. The chamber parts of test numbers A1 and A2 had an oxide barrier layer formed thereon. It can be seen that the chamber component (with or without an oxide barrier layer) treated using the fluorination process shows a significantly higher concentration of F than the test number R, thus representing the alumina surface of the chamber component Saturated with fluorine. That is, when the chamber component is processed using a fluorination process, the aluminum fluoride layer 206 is formed on the surface of the chamber component 202.

It should be understood that the fluorination process using the above solution hardly etches or corrodes the alumina surface of the chamber component 202, thus protecting the alumina surface of the chamber component 202 and increasing the number of times the chamber component 202 can be cleaned. As used herein, "nearly etched or corroded" (or a derivative thereof) is intended to mean that alumina in the chamber part 202 is determined by visual inspection or micrometric accuracy to the nearest tenth of an inch (0.0001 inch). No detectable corrosion on the surface. In addition, although hydrofluoric acid is discussed, it is envisioned that other chemical agents such as sodium fluorohydride, ammonium bifluoride, and ammonium fluoborate may also be used.

In some implementations, the exposed surface of the chamber component 202 (or at least will deposit the oxide barrier layer 204 and / or fluorinated oxide) before the oxide barrier layer 204 and / or the aluminum oxyfluoride layer 206 is formed on the chamber component 202. The surface of the aluminum layer 206 may be roughened by abrasive blasting (which may include, for example, bead blasting, sand blasting, soda blasting, powder blasting, and other particle blasting techniques) to have any Expect texture. Sand blasting can also enhance the adhesion of the oxide barrier layer 204 and / or the aluminum fluoroaluminum layer 206 to the aluminum surface of the chamber component 202. Other techniques may be used to roughen the exposed surface of the chamber component 202, including mechanical techniques (e.g., wheel grinding), chemical techniques (e.g., acid etching), plasma etching techniques, and laser etching techniques. The exposed surface of the chamber component 202 (or at least the surface on which the oxide barrier layer 204 and / or the aluminum fluoride layer 206 is deposited) may have a thickness from about 16 micro inches (μin) to about 220 μin, such as from about 32 μin to about 120 μin , For example, an average surface roughness in a range from about 40 μin to about 80 μin.

After the chamber component 202 is processed using a fluorination process, the chamber component may be installed in a processing chamber performing a plasma process.

Benefits of this disclosure include: by exposing chamber components to a solution containing hydrofluoric acid (HF), ammonium fluoride (NH ₄ F), ethylene glycol, and water (H ₂ O) at room temperature for at least In 30 minutes, a protective fluoroaluminum oxide layer was formed on the aluminum or alumina surface of the chamber part. Once a protective fluoroalumina layer is formed, the underlying alumina surface is protected from hydrofluoric acid. Ethylene glycol also delays the etching reaction between the alumina surface and hydrofluoric acid, thus protecting the underlying alumina surface from excessive etching of hydrofluoric acid. Due to the formation of the fluoroaluminum oxide layer, the amount of unstable aluminum fluoride (AlFx) on the alumina surface is reduced. In addition, the aluminum fluoroalumina layer slows the sweep of F radicals onto the aluminum surface of the chamber components, and therefore improves the amount of etching in the processing equipment without AlFx contamination. Therefore, etch rate drift is avoided and chamber stability is improved.

Although the foregoing content relates to the implementation of the disclosure, other and further implementations of the disclosure may be designed without departing from the basic scope of the disclosure.

100‧‧‧ Method

102‧‧‧block

104‧‧‧box

106‧‧‧box

202‧‧‧ chamber components

203‧‧‧Subject

204‧‧‧oxide barrier

205‧‧‧outer surface

206‧‧‧Alumina fluoride layer

207‧‧‧Core Subject

209‧‧‧aluminum or coated aluminum

211‧‧‧outer surface

Embodiments of the present disclosure that are briefly summarized above and discussed in more detail below can be understood by referring to the illustrative embodiments of the disclosure described in the accompanying drawings. It should be noted, however, that the drawings illustrate only typical implementations of the disclosure, and are therefore not to be considered limiting of its scope, as the disclosure may allow other equally effective implementations.

FIG. 1 depicts a flowchart of a method for processing chamber components for use in a substrate processing chamber.

2A to 2B illustrate perspective views of a portion of a chamber component during various stages of a method according to the flowchart of FIG. 1.

FIG. 2C illustrates a perspective view of a portion of a chamber component according to an implementation of the present disclosure.

To facilitate understanding, wherever possible, the same reference numbers will be used to identify the same elements that are common to the drawings. The drawings are not drawn to scale and are simplified for clarity. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

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Information on foreign deposits (please note in order of deposit country, institution, date, and number) None

Claims (20)

A chamber component for use in a processing chamber includes: a body used in a plasma processing chamber; an oxide barrier layer formed on an exposed surface of the body On at least a part, the oxide barrier layer has a density of about 2 gm / cm ³ or more; and a fluoroaluminum oxide layer formed on the oxide barrier layer, the fluoroaluminum oxide layer having about A thickness of 2 nm or more. The chamber component of claim 1, wherein the body comprises aluminum, stainless steel, aluminum oxide, aluminum nitride, or ceramic. The chamber component according to claim 1, wherein the body is formed of a single piece of aluminum, stainless steel, aluminum oxide, aluminum nitride, or ceramic. The chamber component according to claim 1, wherein the body is formed of a single piece of stainless steel, and then coated with aluminum, aluminum oxide, aluminum nitride, or ceramic. The chamber component according to claim 1, wherein the main body comprises: a core; an aluminum coating formed on the core. The chamber component of claim 1, wherein the oxide barrier layer is a native oxide. The chamber component according to claim 1, wherein the aluminum fluoroaluminum layer has a thickness of about 4 nm to about 12 nm. The chamber component according to claim 1, wherein the body has an average surface roughness of about 16 μin to about 220 μin. A method of processing a chamber component, comprising: exposing at least a portion of an exposed surface of a chamber component body to oxygen, wherein the exposed surface of the chamber component body includes aluminum; and 5 ° C to about 50 ° C exposure to a solution including hydrofluoric acid (HF), ammonium fluoride (NH ₄ F), ethylene glycol, and water for about 30 minutes or more to block the oxide At least a portion of the layer is converted into a layer of aluminum fluoride. The method according to claim 9, wherein the oxide is formed in a high temperature oxidation furnace using an oxygen-containing gas including atomic oxygen (O), molecular oxygen (O ₂ ), ozone (O 3), or steam (H ₂ O). Barrier layer. The method of claim 10, wherein the oxide barrier layer has a density of about 2 gm / cm ³ or more. The method of claim 9, wherein the oxide barrier layer is formed using ozone / TEOS through a non-plasma-based deposition process below atmospheric pressure. The method of claim 12, wherein the oxide barrier layer is subjected to an annealing process in a nitrogen environment. The method of claim 13, wherein the oxide barrier layer has a density of about 10 gm / cm ³ or more. The method of claim 9, wherein the oxide barrier layer is a native oxide. The method of claim 9, wherein the oxide barrier layer has a thickness of about 2 nm to about 18 nm. The method of claim 9, wherein the chamber component body is exposed to the solution at a temperature range of about 20 ° C to about 30 ° C. The method according to claim 9, wherein the ammonium fluoride is a solid or an aqueous solution. A method of processing a chamber component, comprising: forming an oxide barrier layer on at least a portion of an exposed surface of a chamber component body, wherein the exposed surface of the chamber component body includes aluminum; and The chamber component body is exposed to a temperature of about 5 ° C to about 50 ° C and includes about 29% by volume of 49% hydrofluoric acid (HF), about 11% by volume of 40% ammonium fluoride (NH4F), and 60%. A volume percent of 100% ethylene glycol is about 30 minutes or more, and an aluminum fluoride fluoride layer is formed on the oxide barrier layer. The method of claim 19, wherein the oxide barrier layer has a density of about 2 gm / cm ³ or more.